FtsZ is an essential tubulin-like GTPase that assembles into a ring structure at the site of cell division and recruits other essential division proteins to form the septal ring critical for bacterial cytokinesis. FtsZ is widely conserved in the Bacterial kingdom, including most pathogens and biothreat agents, but is absent in the mitochondria of higher eukaryotes. The essentiality of FtsZ in bacterial cell division, its widespread conservation, its low amino acid identity with tubulin, and its absence in mammalian cells make it an attractive broad-spectrum antibacterial target. Using FtsZ protein-based as well as chemical genetic high throughput screens against small molecule libraries, a number of hits have been identified that cause cell filamentation and bacterial lethality. The whole-cell screens have identified two classes of molecules that cause lethal filamentation with or without affecting FtsZ activity, suggesting inhibition of other essential but as yet unidentified septation targets. One goal of the project is to use these division inhibitors as chemical tools to study septal ring assembly and to identify and validate septation-specific non-FtsZ targets. Another goal is to use the promising inhibitors as chemical scaffolds for analog synthesis and structure-function relationship studies. This effort may aid the development of potent therapeutic leads that target cell division in bacterial pathogens of public health importance and in biothreat agents.